Spanish 3 need help u l

Achemist mixes 4 liters of one acid solution with 10 liters of a 40% solution, resulting in a 30% acid solution. what is the value of x, the acid concentration of the first solution

Fill in the blank with the correct form of preterite or imperfect of the verb in parentheses. nosotros to puerto rico. (vivir)

Which verb form correctly completes this sentence? a nosotros nos los cuentos porque son muy breves y fáciles de leer. a. gustan b. gusta c. gustas d. gustamos